Improvement in door-latches



tions within its limit of motion.

, UNITED STATES,

PATENT OEETCE.

JONATHAN DEARBORN, OF SEABROOK, NEW HAMPSHIRE.

IMPROVEMENT IN DOORLATCHES.

.To all whom it may concern:

Be it known that I, JONATHAN DEAREOEN, of Seabrook, in the county of Rockingham and State of New Hampshire, have invented a new and useful Improvement in Door Bolts or Fasteners; and I do hereby declare the same to be fully described in the following specification and represented -in the accompanying drawings, of which- Figure 1 denotes a side elevation of a portion of a door having my invention applied thereto; Fig. 2, a vertical and longitudinal section of the same, while Figs. 3 and 4 denote side views of the lock-case. Y

'Ihe nature of my invention consists in a peculiar construction and arrangement of a self-operating lever with respect to the boltcase and thespindle of the knob or knobs, whereby the said bolt is caused to operate in manner as will be hereinafter described.

It is a fact well known that the ordinary spring-bolts as applied to doors for maintaining them in a closed state are very objectionable on account of the liability of their springs becoming either broken or deranged. To so construct and apply the bolt to its case as to render the former positive in its movements and at the same time dispense with the use of a spring has Vbeen the object of my invention.

ln the drawings, A denotes the bolt-case, which is constructed of metal, a being the main vertical plate,while b is an inclosing plate or guard, which surrounds the rear portion of the curved bolt and has each of its ends soldered or otherwise properly affixed to the plate a. The inner horizontal surface of the upper part of the guard may be so arranged as to serve as an estopper to the bolt when it has reached its limit ot' elevation. c represents another guard plate or bar, which is bent at its lower end, and is properly attached to the plate a. l The said guard is rmly secured to the plate cY by means of rivets passing through each of the plates a and c, and a bar, d, of wood, this lat-l ter being of a little greater width than that of the bolt B. rlhe said bolt is made of a curvedy form, as seen in the drawings, it being so pivoted near its upper end, by means of a pin, e, which passes horizontally through the plates ct and c, thatit can play freely in vertical direc` The lower end of the said bolt is formed with a Vertical bevel in the ordinary manner, and auch end slides freely through a slot formed in the faceplate I, as seen in the drawings. The said faceplate is disposed at right angles to the plate a,

and is secured to the block d by means of screws or rivets passing into or through the same. The said plate serves to conne the bolt-case to the door by means of screws passed through it in the ordinary manner. 'Through the central portion of the said curved bolt and transversely of the same a cylindrical or other proper-shaped hole, g, is made for reception of the spindle h of the knob or knobs C or O. The said spindle may be formed with a male screw on each of its ends, to work in conjunction with a corresponding female screw formed in each of the saidknobs; or the said spindle may be so formed as not vto extend entirely through the door, but simply through one side of the door, the platea, and into the bolt B, such construction being especially adapted for closets, &c.

D is a curved-slot made vertically in the plate a, as seen in Fig. 3. rIhis slot is of such length as will allow the spindle h to have a sufficient upward 'and downward movement either to withdraw the end ofthe bolt from its mortise in the doorway-frame or to project into the same, as circumstances may require.

D D are two metallic plates placed, respectively, on each side of the door opposite the bolt-case, one of such plates being shown in c side View of Fig. l, each having a slot or hole made through it of a sufficient size to allow the spindle to have such vertical movements im` parted toit as will either draw thelocking end of the bolt into the case or force it out therefrom, as circumstances may require. Fur-. thermore, in order to lock the door or prevent it from being opened after it may have been closed, I dispose ou the face ofthe plate D, as

seen in Fig. 1, a notched bar. or dog, Z, the same being pivoted so as to turn freely in vertical directions. The said notch is so formed in the bar Z that when brought to bear 'upon the spindle h it shall retain such spindle in its lowest position, and thus preventthe retraction of the bolt B. y

By my peculiar construction of the bolt B and its arrangement and suspension within the case, as set forth, the whole weight of the bolt operates to force the end of the bolt into its locking-recess,and, besides this, the weight of the spindle and its knob or knobs also aid in forcing the bolt forward into its locking-recess. v

From the above it will be seen that my improved bolt is so constructed and arranged that its own gravitating power shall force the lower end of the boltV into its locking-recess whenever it may be brought into line with the same. The superadded weight of the spindle Vand its knobs renders its forward locking movement certain. The curved form of the bolt I i have adopted as being the most compact; but 

